1. Field of the Invention
This invention relates to an engine mount.
2. Description of the Related Art
In general, engine mounts are used for supporting an automobile engine inside the engine room to the vehicle body member in vibration-insulating manner.
For example, a conventional engine mount is shown in FIG. 6, which is a longitudinal sectional view. This engine mount 100 is a liquid-sealed type vibration-proof mount which comprises an upper fitting 101 to be attached to the engine side not shown, a main body fitting 103 to be fixed to the vehicle body member 100 supporting the engine through a bracket 102, a vibration-insulating base 104 made of rubber elastomer interconnecting the upper fitting and the main body fitting, a diaphragm 105 opposed to the vibration-insulating base 104 inside the main body fitting 103, and a liquid-sealed chamber 106 constituting the interior enclosed by the diaphragm.
With the construction of the engine mount 100 of the type shown in FIG. 6, the vehicle body member 110 below the engine mount may be provided with an opening 111. In case where the opening 111 is thus provided, extraneous matter (EM) such as pebbles, gravel is likely to enter the engine room to intrude through the opening 111 into the member 110.
Once entering the member 110, such extraneous matter is very difficult to remove, and in order to prevent extraneous matter from intruding from the opening 111, for example, a separate rubber cap or the like may be fitted to the opening to close it. However, this expedient of closing by means of a separate component from the engine mount causes an increase in number of the component pieces assembled, which leads to a problem of cost increase.
In view of the prior art problem, this invention has been made and has for an object to provide an engine mount capable of preventing extraneous matter from entering through an opening provided in a vehicle body member without entailing the increase in number of component pieces.
This invention consists in an engine mount adapted to be installed above an opening of a vehicle body member to support an engine in a vibration-insulating manner, comprising a main body fitting having a cylindrical drum, an upper fitting, a vibration-insulating base made of rubber elastomer interconnecting the main body fitting and the upper fitting, a diaphragm disposed within the main body fitting so as to be opposed to the vibration-insulating base, and a liquid-sealed chamber, a part of whose wall is formed by the diaphragm, wherein a rubber extension of generally cylindrical form is provided to extend downwardly from a lower peripheral portion of the diaphragm so as to be made integral with it, thereby to close the opening of the vehicle body member.
According to the engine mount of this invention, the opening provided in the vehicle body member located downwards can be closed by the rubber extension of a generally cylindrical form made integral with the diaphragm, so that it is possible to avoid the intrusion of extraneous matter from the opening without the necessity of additional component pieces.
In the engine mount of this invention, it is preferred that the aforementioned rubber extension project downwardly of the opening of the aforementioned member, and be turned up at a lower projecting end thereof toward its outer circumference so that the turnup end may come in contact with a lower surface of a peripheral edge of the opening of the member thereby to close the opening.
By turning up the rubber extension and bringing the turnup end into contact with the lower surface of the peripheral edge around the opening in this manner, it is possible to close the opening with no clearance and to absorb dimensional dispersion among the members.
According to another embodiment of the engine mount in this invention, the rubber extension is bent and turned up toward its outer circumference so that the bent portion is in contact with an upper surface of the circumferential edge around the opening of the member thereby to close the opening.
Thus by bringing the bent portion of the rubber extension into contact with the upper surface of the circumferential edge around the opening, it is possible to shut off the opening without clearance and to absorb dimensional dispersion among the members.
In the preceding engine mount, the rubber extension further may be provided with a thin-walled portion that serves as a bending portion when turned up.
By this means it is possible to determine the bending and turning-up position of the rubber extension at a definite position and to adjust easily the height of bending location by varying the position of the thin-walled portion. Since the rubber extension is bent at the thin-walled portion, the turnup portion is less prone to revert to the original state.
In the preceding engine mount, it is also possible to further provide a thick-walled portion at an entire lower circumferential extremity of the cylindrical rubber extension.
In that case, when the rubber extension is turned up, the turnup end is of the thick-walled portion, which is difficult to unfold in nature, so that it is possible to prevent the turnup portion from reverting to the initial state.